Patent GB-730959-A (GB)
Title: Improvements in or relating to electrically heated cooking apparatus
IPC: A47J37/01
Filed: 1951-11-21
Abstract: 730,959. Electric cooking apparatus. FEJER, G. Feb. 23, 1953 [Nov. 21, 1951 ; May 7, 1952], Nos. 27365/51 and 11512/52. Class 39 (3). Apparatus for slow cooking comprises a support 11 for a cooking utensil 9, a heatinsulated cover 8 over the utensil and a temperature-controlled electric heater 19 to maintain the food at a constant temperature, the heater 19 and its thermostatic control unit being carried by the support 11 to form therewith a unitary structure readily detachable from a base 1. The food may first be heated to a higher temperature than that at which it is to be maintained, and a bimetallic or fluidoperated thermostat 18 is brought into action when the cover is placed over the utensil. In Fig. 2, the heating unit 19 and a thermostat 18 are mounted by ball-and-socket joints 16 on a lever 13 pivoted on a spindle 14 supported on a bridge member 12 extending across an oval flanged rim member 11 supporting the utensil 9 and fitting into an oval base member 1 with an outer rim 5 receiving the cover 8. The lever 13 is biased by a spring 20 so as normally to position the heater 19 against the bottom of the utensil 9. The end of the lever extends outside the base 1 and may engage one of several notches 23 in a vertical slot in the rim 5 of the base 1, so as to hold the heater at varying distances from the utensil. The cover 8 is of heat-insulating material, e.g. resin-bonded paper pulp or asbestos fibres with a reflecting metal interior surface or is an aluminium sheet with an outer layer of cork, expanded plastic or asbestos. When cooking has proceeded to a certain extent, the lever 13 is depressed by putting the cover 8 in the rim 5, the thermostat 18 moves into contact with the base of the utensil and the heater 19 is lowered, whereby the utensil is maintained at a constant temperature. The rim member 11 carries an electric socket and is removable with the heater 18. A drip pan 25 is carried by tubes of inverted U shape bent up and outwardly to form handles on the base 1. The thermostat may comprise a bimetallic strip or may be fluid-operated. In Fig. 5 a flat, oval or circular electric heater 34 is mounted in a flanged rim 35 in a base member 30 and carries on its lower side one end of a bimetallic strip 36, the free end of which engages an adjustable spring 37, the members 36, 37 being connected in the electric supply to the heater. The bimetallic strip 36 flexes upwardly when heated and when it separates from the spring 37, current supply to the heater is cut off. A rotatable cam 39 is mounted on a vertical spindle 38 extending downwardly from the heater through the spring 37, which is pressed down on to the cam by a compression spring 41 on the spindle. The cam 39 is rotated by a lever 40 on the spindle so as to adjust the distance of the end of the spring 37 from the bimetal 36 and hence to vary the temperature of operation of the thermostat. The end of the lever 40 extends through a horizontal slot 43 in the casing 30 and may engage one of several notches therein. When the cover 8 is put on a rim 31 on the base 30, the lever 40 is depressed from the notches and is rotated by a spring to the minimum temperature position of the thermostat. Several such heaters may be mounted in one frame, each heater having a hinged or removable lid. According to the first Provisional Specification, the heater may be an electric lamp, and the casing has a window, and a thermostat may be in contact with the lid.